Abstract : The interest in the molecular band systems of nitrogen as discussed has grown out of two lines of investigation. One of the programs was a study of the infrared absorption line intensities of simple molecules. The other was a high resolution effort in the vacuum ultraviolet from which values of the spectroscopic constants to a quite high precision were obtained for the nitrogen molecule. The junction of these programs has resulted in the extension of the electronic spectrum of molecular nitrogen well into the infrared and in the generation of a considerable body of tabular data bearing on the intensity of the various emission features of nitrogen in all spectral regions. The results should be of interest to those working on various types of discharges in air, nitrogen, or any other mix which is not vigorously uncontaminated. In particular, the conclusions have a clear bearing on relative intensities in the aurora and the emphasis in much of the discussion is from that point of view. (Author)